Brush

ABSTRACT

A brush is formed by a bundle of straight parallel extruded plastic filaments which project from one end portion of an extruded plastic sheath, the portion of the bundle within the sheath completely surrounding a wedge. The sheath is attached to a handle, and the filament bundle is suitably of generally rectangular cross-section, to produce a flat brush. The brush is made by continuously extruding a rope consisting of straight parallel filaments of a plastic material in a bundle around a continuously advanced core which is easily sectionable. Continuously extruded around the core and filament bundle is a sheath of plastic material. The rope is sectioned into predetermined lengths, and part of the sheath is stripped from each length to expose the filaments. The filament ends are anchored to the sheath and to one another, and the core is severed adjacent the mouth of the sheath, which is attached to the handle. The handle may instead be formed by shaping the end of the sheath remote from the filaments. The core is formed with locally weakened portions extending transversely of the length of the extruded rope, to facilitate severing of the core.

United States Patent 1191 Leigh 1451 Mar. 18, 1975 BRUSH [75] Inventor:Monty Leigh, Boreham Wood,

England [73] Assignee: Leng-Armac Limited, Boreham Wood, Hertfordshire,England [22] Filed: Aug. 16, 1973 [21] Appl. No.: 388,917

[30] Foreign Application Priority Data Aug. 18, 1972 United Kingdom38757/7; Oct. 13, 1972 United Kingdom 47412/72 June 1 1, 1973 UnitedKingdom 27645773 [52] US. Cl 15/159 A, 15/193, 15/204,

15/DlG. 4, 161/175, 264/174, 264/147, 300/21 [51] int. Cl A46b 3/06,A46b 9/00, A46d H08 [58] Field of Search 15/159, 159 A, 191, 192,15/193, 194, 204, DIG. 4; 300/21; 264/174,

[56] References Cited UNITED STATES PATENTS 1,103,515 7/1914 Huschl5/l59RX 1,616,858 2/1927 Jacob 15/204 2,581,561 l/l952 Shaw 15/159 A3,266,624 8/1966 Shaw et a1 4. 15/159 R 6/1974 Weiss 300/21 FOREIGNPATENTS OR APPLICATIONS 931,517 7/1963 United Kingdom 15/193 PrimaryExaminer-Peter Feldman Attorney, Agent, or FirmWaters, Roditi, Schwartz& Nissen [57] ABSTRACT A brush is formed by a bundle of straightparallel extruded plastic filaments which project from one end portionof an extruded plastic sheath, the portion of the bundle within thesheath completely surrounding a wedge. The sheath is attached to ahandle, and the filament bundle is suitably of generally rectangularcross-section, to produce a flat brush. The brush is made bycontinuously extruding a rope consisting of straight parallel filamentsof a plastic material in a bundle around a continuously advanced corewhich is easily sectionable. Continuously extruded around the core andfilament bundle is a sheath of plastic material. The rope is sectionedinto predetermined lengths, and part of the sheath is stripped from eachlength to expose the filaments. The filament ends are anchored to thesheath and to one another, and the core is severed' adjacent the mouthof the sheath, which is attached to the handle. The handle may insteadbe formed by shaping the end of the sheath remote from the filaments.The core is formed with locally weakened portions extending transverselyof the length of the extruded rope, to facilitate severing of the core.

18 Claims, 9 Drawing Figures BRUSH The present invention concerns animproved brush.

Conventionally brushes have been manufactured by fastening the bristlesinto a metal ferrule attached to a wooden or plastic brush handle.

It has already been proposed to use filaments of a plastic materialinstead of natural bristles, but brushes produced in this way still usea metal ferrule for holding the filaments and attaching them to thehandle.

In many applications, however, it is highly advantageous to haveavailable a brush with no metal parts.

In the prior art a rope has been produced in the form of parallelfilaments of plastic material surrounded by a plastic sheath. It hasbeen proposed to cut such rope into lengths from which the sheath isstripped away at one end to expose the filaments, the filaments andsheath being fused or bonded together and a further bond to the wall ofthe sheath at the opposite end. The resulting assembly forms a brush,and the brushes thus formed are suitable for a variety of applications.

Such brushes are of limited usefulness, however, in the larger sizescommonly in use. In conventional brush manufacture larger brushes have ahollow construction, in that a block of material (referred to in the artas a plug or wedge, although not necessarily wedge-shaped) is driveninto the centre ofthe group of bristles within the ferrule.

The present invention is intended to provide an improved method ofmanufacturing brushes by means of a continuous extrusion process andwith which larger sized brushes can be produced without the attendentdisadvantages of unwedged construction.

In one aspect the invention provides a brush head formed by a bundle ofstraight parallel extruded plastic filaments which project from oneportion of an extruded plastic sheath, the portion of the bundle withinthe sheath surrounding a wedge.

The invention also includes a brush comprising a brush head as definedin the preceding paragraph, the sheath being attached to a brush handle.

The filament bundle is suitably of generally rectangular cross-section,to produce a flat brush or brush head.

In a further aspect the invention provides a method of making a brushhead, comprising the steps of: continuously extruding a rope consistingof straight parallel filaments of a plastic material in a bundle arounda continuously advanced core which is easily sectionable; continuouslyextruding around the core and filament bundle a sheath of plasticmaterial; sectioning the rope into predetermined lengths; stripping awaypart of the sheath from each length to expose the filaments; anchoringthe filament ends to the sheath and to one another; and severing thecore adjacent the mouth of the sheath.

The filament bundle is suitably of generally rectangular cross-sectionto provide a flat brush head.

The core is preferably formed with locally weakened portions extendingtransversely of the length of the rope.

The unstripped portion of the sheath on each length may be displacedaway from the exposed filaments to leave an open-ended hollow spacewithin the sheath, before the filament ends inside the sheath are bondedtogether and to the sheath. A brush handle may then be inserted into theopen end of the sheath and the sheath fastened to the handle.

The invention also includes a method as defined in the precedingparagraph but three, in which longitudinally-extending ribs are formedby the extrusion process on the inside surface of the sheath and/or theoutside surface of the core, the ribs extending into the filament bundleto locate the filaments.

It has been found that little difficulty is experienced in extruding anannular bundle of filaments, but when the filament bundle has thegeneral shape of a hollow rectangle, to produce a flat brush, there issome tendency for the filaments in the bundle to migrate around itscross-section.

This produces an uneven distribution ofthe filaments in the finishedbrush.

The provision of the longitudinally-extending ribs of any suitablecross-section is intended for locating the filaments of the bundle.

The invention will now be described in more detail, by way of exampleonly and with reference to the accompanying diagrammatic drawings inwhich:

FIG. 1 is a cross-section through a continuously extruded rope used inthe manufacture of a brush;

FIG. 2 is a side view of a length cut from the rope;

FIG. 3 shows the rope section after stripping away a portion of thesheath;

FIG. 4 shows the next step in the manufacture of the brush;

FIG. 5 shows a side elevation of the finished brush;

FIG. 6 is a side view of a core of the rope forming a wedge in thefinished brush;

FIG. 7 is a cross-section through a continuously extruded rope used inthe manufacture of a brush;

FIG. 8 is a cross-section through an alternative form of rope; and

FIG. 9 schematically shows one method of weakening'the core of the ropeat regular intervals.

Referring to FIG. I, a continuously extruded rope consists of straightparallel plastic filaments l in the form of a bundle of generallyrectangular cross-section around a core 2 also of generally rectangularcrosssection. A plastic sheath 3 is extruded over the filament bundle l.

The core 2 has the form shown in side elevation in FIG. 6, and iscontinuously advanced at the speed of extrusion of the filaments 1 andsheath 3.

The extruded rope is sectioned into predetermined lengths, one of whichis shown in side elevation in FIG. 2. The sheath 3 is then stripped awayfrom part of each section to expose the filaments l, as shown in FIG. 3.The filaments will tend to splay lightly as shown in the Figure.

The remaining portion of the sheath 3 is then bodily displaced on thefilaments l, away from their exposed ends. An open-ended hollow space 4is thus formed within the sheath 3, as shown in dashed outline in FIG.4. The core 2 is shown in chain-dotted outline in FIG. 4.

The filament ends inside the sheath 3 are then bonded together and tothe sheath, suitably by fusing.

The core 2 is then severed adjacent the mouth of the sheath from whichthe filaments 1 project, to form a wedge 5 shown in dashed outline inFIG. 5.

To facilitate severing the core to form the wedge, the core has the formshown in FIG. 6. The core has locally weakened portions extendingtransversely of the length of the extruded rope, in the form of portions6 of reduced cross-section at regular intervals along the length of thecore. The core is suitably of a brittle foamed or otherwise easilysevered material, and the appropriate choice of material may make thereduced cross-section portions unnecessary.

The material for the core is preferably chosen so that the broken-offportions can be re-used to make further core lengths, rather than beingdiscarded and thus wasted.

. The method as so far described results in the production of a finishedbrush head.-

The final stage in the construction of the brush is to I insert a brushhandle 7 into the open end of the sheath 3, as shown in FIG. 5, and toattach the sheath to the handle. This may be done in a conventionalmanner, by means of staples or pins for example or merely glued.

Referring to FIG. 7, a continuously extruded rope consists of straightparallel plastic filaments 1 in the form of a bundle of generallyrectangular cross-section around a core 2 also of generally rectangularcrosssection. A plastic sheath 3 is extruded over the filament bundle l,and has longitudinally-extending ribs 14 formed by the extrusion processon its inside surface. The ribs 14 extend into the filament bundle tolocate the filaments thereof, to compensate for any tendency thefilaments may have to migrate around the bundle cross-section on leavingthe extrusion head. The ribs 14 may be of other cross-sections so as toprovide a toothed appearance for example.

- The alternative form of rope shown in FIG. 8 also has straightparallel plastics filaments l in the form of a bundle of generallyrectangular cross-section around a core 2 also of generally rectangularcross-section with a plastic sheath 3-extruded over the filament bundlel, but in this case longitudinally-extending ribs are formed on theoutside surface of the core 2, by the extrusion process. The ribs 15have the same function as the ribs 14 shown in H6. 7.

It will be appreciated that ribs may be provided on the inside surfaceof the sheath and on the outside surface of the core, but this will notgenerally be necessary, and ribs on one element or the other willusually suffice. I

The ribs are readily produced by appropriately shaping the outletorifice of the extrusion die.-

The core 2 must'be easily sectionable, so that unwanted portions of itin the finished brushes can be broken off.

One way of achieving this, as already mentioned, is by means of reducingthe core cross-section at periodic intervals.

This can be done by extruding the core through a wide outlet aperture,the extrudate being cut to provide lengths of core which are fed intothe extrusion apparatus for the filament bundles and sheath. This methodis not practicable, however, when the core is formed with longitudinallyextending ribs.

FIG. 9 shows one method of achieving a similar periodic weakening of thecore when it is provided with longitudinal ribs. The core 2 with ribs 15leaves the extrusion head 16 and passes between rollers 17 and 18 eachof which carries radially-extending knives 19.

The rollers 17 and 18 rotate in synchronism at such a rate that theperipheral speed of the tips of theblades 19 is substantially equal tothe speed of advance of the core 2.

The synchronism of the rollers 17 and 18 is such that blades cometo-gether two-by-two, as clearly shown in FIG. 9, so as to cut throughthe major part of the core cross-section. Successive cuts in the coreare made by successive pairs of blades, which progressively come intocontact with the core as the rollers rotate. With the core advancingfrom left to right as seen in the Figure the upper roller 17 rotatesanti-clockwise and the lower roller 18 clockwise.

It will be appreciated that FIG. 9 is diagrammatic, and that the shapeof the blades 19 may need to be triangular or of some other suitableform to facilitate carrying out the process.

With certain plastic materials it may be possible to form an integralhandle consisting of an appropriately would be stripped away to exposethe filaments and the core broken off to form a wedge in the manner justdescribed. The other end of the rope length would then be formed into ahandle, perhaps by some form of induction heating and pressingoperation.

The filaments used for the brush bristles may be of polypropylene,polyester or other suitable plastic material, as may the sheath. Thecore may be of a plastics material, but must be chosen so that it can beeasily severed to produce the wedge.

With this method of construction, it is possible to produce a brushhaving no metal parts whatsoever. While it has been stated that thefilament assembly may be stapled or pinned to the brush handle, it willbe appreciated that other fixing methods may be used to avoid the use ofmetal staples or pins.

By appropriate choice of the plastic materials used in the brushconstruction, the following advantages may be realised:

The brush will not be affected by most of the commonly used solvents,and appropriate plastic materials will be inert to acids at ordinarytemperatures.

The brush will not be effectedby alkalis, bleaching agents,'oils orgreases, and will be suitable-for use with a wide variety of polishes,glues, inks, adhesives, paints,

varnishes, lacquers, paints, derusting agents, oven cleaners,penetrating oils, acids and so on.

It has been found that immersion of such a brush in boiling water forone hour has no effect other than a slight splay.

I claim: g

l. A brush head formed by an extruded plastic sheath, a bundle ofstraight parallel extruded plastic filaments which project from one endportion of said extruded plastics sheath, and a wedge, the portion ofthe bundle within the sheath completely surrounding said wedge. I v

2. A brush head as set forth in claim 1, in which said filament bundleis of generally rectangular flat, oval or round cross-section.

3. A brush head as set forth in claim 2, in which the inside surface ofsaid sheath is formed with longitudinally extending ribs that extendinto said filament bundle to locate said filaments.

4. A brush head as set forth in claim 1, in which'the outside surface ofsaid core is formed with longitudinally extending ribs that extend intosaid filament bundle to locate said filaments.

5. A brush head as set forth in claim 1, in which the inside surface ofsaid sheath and the outside surface of said core are formed withlongitudinally extending ribs that extend into said filament bundle tolocate said filaments.

6. A method of making a brush head, comprising the steps of:continuously extruding a rope consisting of straight parallel filamentsof a plastic material in a bundle around a continuously advanced corewhich is easily sectionable; continuously extruding around said core andsaid filament bundle a sheath of plastic material; sectioning said ropeinto predetermined lengths; stripping away part of said sheath from eachlength to expose said filaments; anchoring the ends of said filaments tosaid sheath and to one another; and severing said core adjacent themouth of said sheath.

7. A method as set forth in claim 6, in which said filament bundle is ofgenerally rectangular cross-section to provide a flat brush head.

8. A method as set forth in claim 7, in which said core is of generallyrectangular cross-section.

9. A method as set forth in claim 6, in which said core is formed withlocally weakened portions extending transversely of the length of saidrope.

10. A method as set forth in claim 6, in which the unstripped portion ofsaid sheath on each length is displaced away from the exposed filamentsto leave an open ended hollow space within the sheath, before the endsof said filaments inside said sheath are bonded together and to saidsheath.

11. A method as set forth in claim 6, in which longitudinal!y-extendingribs are formed by the extrusion process on the inside surface of saidsheath, the ribs extending into the filament bundle to locate thefilaments.

12. A method as set forth in claim 6, in which longitudinally-extendingribs are formed by the extrusion process on the outside surface of saidcore, the ribs extending into the filament bundle to locate thefilaments.

13. A method as set forth in claim 6, in which longitudinally-extendingribs are formed by the extrusion process on the inside surface of saidsheath and the outside surface of said core, the ribs extending into thefilament bundle to locate the filaments.

14. A method of making a brush. by:

continuously extruding a rope consisting of straight parallel filamentsof a plastic material in a bundle around a continuously advanced corewhich is easily sectionable;

continuously extruding around said core and said filament bundle asheath of plastic material; section- 6 ing said rope into predeterminedlengths; stripping away part of said sheath from each length to exposesaid filaments;

anchoring the ends of said filaments to said sheath and to one another;severing said core adjacent the mouth of said sheath; and attaching abrush handle to said sheath.

15. A method of making a brush, by:

continuously extruding a rope consisting of straight parallel filamentsof a plastic material in a bundle around a continuously advanced corewhich is easily sectionable; continuously extruding around said core andsaid filament bundle a sheath of plastic material; sectioning said ropeinto predetermined lengths; stripping away part of said sheath from eachlength to expose said filaments;

anchoring the ends of said filaments to said sheath and to one another;severing said core adjacent the mouth of said sheath;

inserting a brush handle into the open end of said sheath;

and attaching said sheath to said handle.

16. A method of making a brush, by:

continuously extruding a rope consisting of straight parallel filamentsof a plastic material in a bundle around a continuously advanced corewhich is easily sectionable; continuously extruding around said core andsaid filament bundle a sheath of plastic material;

sectioning said rope into predetermined lengths;

stripping away part of said sheath from each length to expose saidfilaments; anchoring the ends of said filaments to said sheath and toone another; severing said core adjacent the mouth of said sheath; anddeforming the end of said brush-head remote from said protrudingfilaments to produce an integral brush handle.

17. A brush, comprising a brush head formed by an extruded plasticsheath, a bundle of straight parallel extruded plastic filaments whichproject from one end portion of said extruded plastics sheath, and awedge, the portion of the bundle within the sheath surrounding saidwedge, attached to a handle.

18. A brush as set forth in claim 17, in which said sheath is hollow atthe end opposite the protruding filaments and said handle is insertedinto the hollow end of said sheath and said sheath fastened to saidhandle.

* l =l= l

1. A brush head formed by an extruded plastic sheath, a bundle ofstraight parallel extruded plastic filaments which project from one endportion of said extruded plastics sheath, and a wedge, the portion ofthe bundle within the sheath completely surrounding said wedge.
 2. Abrush head as set forth in claim 1, in which said filament bundle is ofgenerally rectangular flat, oval or round cross-section.
 3. A brush headas set forth in claim 2, in which the inside surface of said sheath isformed with longitudinally extending ribs that extend into said filamentbundle to locate said filaments.
 4. A brush head as set forth in claim1, in which the outside surface of said core is formed withlongitudinally extending ribs that extend into said filament bundle tolocate said filaments.
 5. A brush head as set forth in claim 1, in whichthe inside surface of said sheath and the outside surface of said coreare formed with longitudinally extending ribs that extend into saidfilament bundle to locate said filaments.
 6. A method of making a brushhead, comprising the steps of: continuously extruding a rope consistingof straight parallel filaments of a plastic material in a bundle arounda continuously advanced core which is easily sectionable; continuouslyextruding around said core and said filament bundle a sheath of plasticmaterial; sectioning said rope into predetermined lengths; strippingaway part of said sheath from each length to expose said filaments;anchoring the ends of said filaments to said sheath and to one another;and severing said core adjacent the mouth of said sheath.
 7. A method asset forth in claim 6, in which said filament bundle is of generallyrectangular cross-section to provide a flat brush head.
 8. A method asset forth in claim 7, in which said core is of generally rectangularcross-section.
 9. A method as set forth in claim 6, in which said coreis formed with locally weakened portions extending transversely of thelength of said rope.
 10. A method as set forth in claim 6, in which theunstripped portion of said sheath on each length is displaced away fromthe exposed filaments to leave an open ended hollow space within thesheath, before the ends of said filaments inside said sheath are bondedtogether and to said sheath.
 11. A method as set forth in claim 6, inwhich longitudinally-extending ribs are formed by the extrusion processon the inside surface of said sheath, the ribs extending into thefilament bundle to locate the filaments.
 12. A method as set forth inclaim 6, in which longitudinally-extending ribs are formed by theextrusion process on the outside surface of said core, the ribsextending into the filament bundle to locate the filaments.
 13. A methodas set forth in claim 6, in which longitudinally-extending ribs areformed by the extrusion process on the inside surface of said sheath andthe outside surface of said core, the ribs extending into the filamentbundle to locate the filaments.
 14. A method of making a brush, by:continuously extruding a rope consisting of straight parallel filamentsof a plastic material in a bundle around a continuously advanced corewhich is easily sectionable; continuously extruding around said core andsaid filament bundle a sheath of plastic material; sectioning said ropeinto predetermined lengths; stripping away part of said sheath from eachlength to expose said filaments; anchoring the ends of said filaments tosaid sheath and to one another; severing said core adjacent the mouth ofsaid sheath; and attaching a brush handle to said sheath.
 15. A methodof making a brush, by: continuously extruding a rope consisting ofstraight parallel filaments of a plastic material in a bundle around acontinuously advanced core which is easily sectionable; continuouslyextruding around said core and said filament bundle a sheath of plasticmaterial; sectioning said rope into predetermined lengths; strippingaway part of said sheath from each length to expose said filaments;anchoring the ends of said filaments to said sheath and to one another;severing said core adjacent the mouth of said sheath; inserting a brushhandle into the open end of said sheath; and attaching said sheath tosaid handle.
 16. A method of making a brush, by: continuously extrudinga rope consisting of straight parallel filaments of a plastic materialin a bundle around a continuously advanced core which is easilysectionable; continuously extruding around said core and said filamentbundle a sheath of plastic material; sectioning said rope intopredetermined lengths; stripping away part of said sheath from eachlength to expose said filaments; anchoring the ends of said filaments tosaid sheath and to one another; severing said core adjacent the mouth ofsaid sheath; and deforming the end of said brush-head remote from saidprotruding filaments to produce an integral brush handle.
 17. A brush,comprising a brush head formed by an extruded plastic sheath, a bundleof straight parallel extruded plastic filaments which project from oneend portion of said extruded plastics sheath, and a wedge, the portionof the bundle within the sheath surrounding said wedge, attached to ahandle.
 18. A brush as set forth in claim 17, in which said sheath ishollow at the end opposite the protruding filaments and said handle isinserted into the hollow end of said sheath and said sheath fastened tosaid handle.